1. Field of the Invention
The invention relates to a reactor provided with a cooler. The reactor is a passive element that uses a coil, and may also be referred to as an “inductor”.
2. Description of Related Art
Electric vehicles including hybrid vehicles are equipped with a power converter that converts output power of a battery to power suitable for driving a running motor. The power converter may include not only an inverter circuit that converts direct current into alternating current, but also a voltage converter circuit. A power converter for an electric vehicle handles large current, so devices with a large allowable current are also employed for the devices used for the inverter circuit and the voltage converter circuit.
A device with a large allowable current generates a large amount of heat. One device that generates a particularly large amount of heat is a reactor that is included in a voltage converter circuit. Therefore, technology to efficiency cool the reactor is necessary. For example, Japanese Patent Application Publication No. 2008-198981 (JP 2008-198981A) and Japanese Patent Application Publication No. 2005-045960 (JP 2005-045960A) propose structures in which a reactor is tucked into a cooler. In particular, JP 2008-198981 A describes a structure in which a reactor and a semiconductor module that includes a switching element are alternately sandwiched by a plurality of flat plate-shaped coolers.
Regarding the reactor, technology described in Japanese Patent Application Publication No. 2001-244123 (JP 2001-244123A) and Japanese Patent Application Publication No. 2011-082489 (JP 2011-082489A) is known. JP 2001-244123 A describes a reactor suitable to be surface-mounted. JP 2011-082489 A describes a reactor that uses a coil wound flatwise. A “coil wound flatwise” refers to a coil in which a flat wire is wound such that a flat surface overlaps with itself in a radial direction of a coil axis. The coil axis may also be referred to as a winding axis.